import math
x1,y1,x2,y2 = map(float,input().split())
a = abs(x1-x2)
b = abs(y1-y2)
d = math.sqrt(a ** 2 + b ** 2)
print(d) import math math x1,y1,x2,y2 = map(float,input().split()) x1 map(float,input().split()) map float input().split() ().split () input split y1 x2 y2 a = abs(x1-x2) a abs(x1-x2) abs x1-x2 x1 x2 b = abs(y1-y2) b abs(y1-y2) abs y1-y2 y1 y2 d = math.sqrt(a ** 2 + b ** 2) d math.sqrt(a ** 2 + b ** 2) math.sqrt math sqrt a ** 2 + b ** 2 a ** 2 a 2 b ** 2 b 2 print(d) print d b = abs(y1-y2) abs(y1-y2) b x2,y2 = map(float,input().split()) map(float,input().split()) x2 y1,x2,y2 = map(float,input().split()) map(float,input().split()) y1 a = abs(x1-x2) abs(x1-x2) a d = math.sqrt(a ** 2 + b ** 2) math.sqrt(a ** 2 + b ** 2) d x1,y1,x2,y2 = map(float,input().split()) map(float,input().split()) x1 y2 = map(float,input().split()) map(float,input().split()) y2
import math
x1,y1,x2,y2 = map(float,input().split())
a = abs(x1-x2)
b = abs(y1-y2)
d = math.sqrt(a ** 2 + b ** 2)
print(d)
